putc/fputc incorrect return?

[tlaronde@polynum.com]

Hello,

I have been investigating a failure to compile METAFONT fonts on present
version of 9front and found the culprit.

When writing a binary file, putc is used and the macro invoking it was
testing the return not against EOF but against the byte supposed to be
written.

The problem is that, apparently now, putc is returning a signed char
promoted to a signed int, meaning that when the byte written has the
higher bit set, all the higher bits are set in the int returned:

I write, say 0xaa, it returns 0xffffffaa. So when comparing, this
failed.

But the problem is that if I write 0xff it returns 0xffffffff that is
EOF...

Isn't putc/fputc supposed to return a "char" as a value that is
0x000000nn so precisely one can differenciate from EOF error?

Best regards,
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                     http://www.kergis.com/
                       http://www.sbfa.fr/
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